1. Field of the Invention
The present invention relates generally to the comminution of solid materials. More particularly, this invention relates to an apparatus used to reduce the size of solid materials into smaller components by means of a processor-controlled liquid jet. More particularly, the present invention relates to an apparatus for separating a vehicle tire into its components using a processor-controlled high velocity liquid jet.
2. Related Art
The disposal of used vehicle tires presents an ever increasing environmental concern. In California alone, over 28 million tires require disposal each year. A tire disposal apparatus and process that balances an environmentally friendly and cost effective approach is crucial to the resolution of this problem.
Traditional methods of tire disposal include burying tires in landfills, either whole or shredded. The disadvantage to burying whole tires is the tremendous volume of space they occupy in already scarce landfills. In addition, whole tires have a tendency to resurface over time when the dirt with which they are covered settles. Shredded tires take up less space in landfills, however, the cost of shredding tires is quite high due to the high capital expense of current tire shredding machinery and the high maintenance costs associated therewith. Burying tires, whole or shredded, also results in the waste of useful material that may be reclaimed from the tires, such as rubber and steel.
As mentioned above, new tire disposal methods are needed that do not tax scarce landfill space and that efficiently reclaim the material of used tires. There are various uses for the reclaimed materials of tires. For instance, crumb rubber may be used in asphalt to make roads smoother and quieter, in new tires and retreads, in composite materials such as thermoplastics and in various industrial applications including the production of roofing materials, siding, automotive parts, flooring and electrical insulation. To this end, an alternative to burying tires has been to use spent tires as a fuel source as Tire Derived Fuel (TDF) in power and cement plants. If tire rubber is burned in furnaces at high temperatures, it will produce energy without noxious fumes. However, in order to achieve an efficient burn with less noxious by-products, the tire rubber must be separated from the other materials of which it is comprised, i.e., the fabric and steel used to reinforce the tread and sidewalls of the tire. Once again, apparatus and methods are currently available to perform such functions, but the machinery is expensive and requires constant maintenance due to the inherent toughness of tires, the variation in materials of which tires are comprised and the various sizes of vehicle tires.
Therefore, what is needed is an economical apparatus for comminuting a tire into the materials of which it is constructed. Further, what is needed is an apparatus that is affordable and easily maintained as well as usable by a variety of users in a variety of locations, i.e., within automobile and truck tire manufacturing facilities, in tire reclamation facilities, etc.
The present invention is directed to a comminution apparatus that is of a simple construction and that can be operated without excessive maintenance. According to the present invention, a vehicle tire of any size or composition can be comminuted with essentially the same comminution apparatus. The comminution apparatus includes a freely moving lance with a nozzle for transforming a liquid into a high velocity liquid jet. The lance is positioned and controlled such that its liquid jet impacts the tire thereby separating it into its component parts.
The comminution apparatus is comprised of two concentric cylindrical tubes that each rotatably support a bearing plate in an interior area thereof. The bearing plates are a distance L apart and rotate at variable speeds n1 and n2 respectively. Each bearing plate includes a bearing in a bearing passage that is located a distance r1 and r2 respectively from a longitudinal center axis Xxe2x80x94X of the concentric cylindrical tubes. The bearings support a lance that is comprised of a flexible hose at an upper end thereof and a nozzle at a lower end thereof.
As the bearing plates rotate, clockwise or counterclockwise the lance orbits about center axis Xxe2x80x94X. A flexible hose which is attached to an upper portion of the lance accommodates the orbital movement of the lance which translates into the movement of the liquid jet emanating from the lance nozzle. By varying bearing plate speeds n1 and n2, distance L and a third variable S (the stand-off distance between the nozzle exit and the article to be comminuted), the liquid jet distribution patterns can be adjusted as necessary to achieve effective tire comminution.
The comminution of the tire may be computer controlled through the use of an imaging device that constantly monitors the comminution process and redirects the liquid distribution of the lance as necessary to efficiently reclaim the material of the tire. Upon completion of the initial comminution process, the tire materials are separated and possibly further processed by additional high velocity liquid jets in a process such as the one described in co-pending application Ser. No. 09/413,489 filed Oct. 6, 1999, incorporated herein in its entirety by reference.
The comminution apparatus of the present invention is of a relatively simple construction and is not subject to the excessive mechanical wear associated with current tire shredding machinery. Further, the tire comminution apparatus of the present invention readily accommodates whole tires of varying sizes without the additional cost or time associated with cutting up a tire into strips or debeading a tire, as required by many of the current tire comminution apparatus.
Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.